1. Field of the Invention
This invention relates generally to brushes and cleaning devices, and more specifically to an improved brush for the cleaning of underwater surfaces, such as swimming pools.
2. Description of the Prior Art
Underwater surfaces, such as the sides and bottoms of swimming pools and boat hulls, tend to accumulate dirt, debris, mineral deposits, and plant or animal growth. Accordingly, it is often important to clean these surfaces, to remove such accumulations and prevent their further buildup.
Numerous brushes and other cleaning devices have been developed to accomplish this task. The most common are simply bristled brushes equipped with extra-long pole handles for reaching the desired area. As a consequence of the geometry involved, cleaning surfaces such as the walls and bottom of swimming pools with these brushes requires extraordinary effort on the part of the user, who is at a great mechanical disadvantage and must exert considerable force on the long pole in a direction perpendicular to the surface to be cleaned, while simultaneously applying the force required for the back-and-forth cleaning movement.
Other cleaning devices have incorporated variations on a structurally inclined "wing" that exerts a force on the brush as it is moved through the water, thus causing the brush to scour the surface to be cleaned more effectively. However, while a brush equipped with a fixed wing can operate well in one direction, for example the downward stroke, on the return stroke it swings uncontrollably outward or upward, creating a large amount of drag and making the return stroke very difficult for the user. Variations on the fixed-wing concept have included devices with shaped wings, for example a ladle-like configuration, which decreases the drag produced on the return stroke. However, this still results in considerable drag in both directions, and difficulty in moving the brush from side to side.
Still other brushes have used pivotable wings which flip over at the end of the downward stroke to present a similarly inclined surface to the water on the return stroke. However, this feature makes such brushes less desirable for pool cleaning, where the purpose is to scour the debris and move it downward toward the drain only, and not move the debris back upward on the return stroke. In addition, this arrangement requires the user to exert a pulling force on the return stroke similar in magnitude to the pushing force required on the downstroke. Such pulling effort can be awkward and tiresome to the user, and also has the unfortunate tendency to pull the user into the water.